> As you rotate, they blur the scene using post-processing. In a completely static scene, this makes sense

No, it doesn't make sense because due to eye movement that's not how turning looks in the real world. Any game that blurs the scene on camera rotation is doing it wrong even if nothing else is moving at the time.

It's impossible to do it correctly without very low latency and high precision eye tracking so the best you can do is to not blur anything that the player might be focusing on.